(a) Field of the Invention
The invention relates to a device for solar tracking, particularly to a device for solar tracking capable of increasing efficiency of a solar panel.
(b) Description of the Related Art
In general, a solar-tracking device is mainly an open-loop solar tracking device. The astronomic theorem is used to master the trajectory of the sunrays and then the incident angle and the azimuth angle of the sunrays at any time and any geographical location can be obtained so that a solar panel can be adjusted accordingly to obtain or acquire the maximum illuminance of the solar panel. However, the open-loop solar tracking device needs a large amount of astronomic data in order to achieve the optimum precision of the system. Besides, the operation of calculating the trajectory of the sun according to the astronomic theorem should be constantly calibrated because the deviation occurs. For example, the deviation occurs when the Earth moves along its orbit.
If the open-loop solar tracking device is installed on a moving object, such as on a car, the result of solar tracking is not as good as expected. Thus, the data of the geographical location should be known. Even if a positioning system such as a global positioning system (GPS) is equipped in the car, it still results in the misjudgment in calculating the orientation of the sunrays according to the astronomic theorem due to the error of the positioning system.
Besides, because the open-loop solar tracking device determines the current position of the sun based on the calculation according to the astronomic theorem, even if the sun is blocked by clouds, the open-loop solar tracking device still moves according to the trajectory of the sun. However, when the sun is blocked by clouds, the sunrays are scattered or refracted by the clouds so that the expected position of the sun is not the best position to acquire the optimum energy. Thus, the open-loop solar tracking device cannot effectively increase the solar energy collection capacity when the sun is blocked by clouds.